The target of the NURISP Collaborative Project was to make new and significant steps towards the NURESIM European Reference Simulation Platform, which is a set of state of the art software devoted to the simulation of normal operation and design basis accidents of light water reactors (BWR, PWR, VVER), while it includes a number of codes covering different physics such as neutronics, thermal-hydraulics, fuel thermo-mechanics, as well as relevant scales, i.e. local (sub-channel or pin), fuel assembly, core and reactor system. During the course of NURISP the codes are extensively benchmarked and validated against experiments, comprising also testing and comparison of different neutron cross-section libraries. The platform is set to provide a more accurate representation of the physical phenomena by developing and incorporating “best estimate” codes, better validated and qualified, faster models in core physics, two-phase thermal-hydraulics and fuel codes.